[BUG] Cowork shows "Virtualization is not available" on Windows 11 Pro 24H2 — all Hyper-V services running, vm_bundles never created

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Cowork should detect that Hyper-V is fully enabled and all services are running, then download and initialize the VM bundle in %LOCALAPPDATA%\Claude\vm_bundles\

What Should Happen?

Cowork shows "Virtualization is not available — Claude's workspace requires Virtual Machine Platform, but the virtualization service is not responding."

All Hyper-V services are confirmed running. The vm_bundles folder is never populated — the VM never attempts to initialize.

| Check | Result |
|---|---|
| OS | Windows 11 Pro 24H2 (Build 26100.4652) |
| Claude Desktop | v1.1.9310.0 (MSIX from claude.ai/download) |
| Installed as administrator | Yes |
| Virtual Machine Platform | Enabled |
| Windows Hypervisor Platform | Enabled |
| Hyper-V (full) | Enabled |
| CoworkVMService | Running / Automatic |
| vmcompute | Running / Manual |
| vmms | Running / Automatic |
| VM Monitor Extensions (systeminfo) | Yes |
| %LOCALAPPDATA%\Claude\vm_bundles | Exists but always empty |

Error Messages/Logs

"Virtualization is not available — Claude's workspace requires Virtual Machine Platform, but the virtualization service is not responding."

No cowork_vm_node.log is ever created. Only log present: chrome-native-host.log
vm_bundles folder exists but is always empty.

Steps to Reproduce

1. Install Claude Desktop v1.1.9310.0 as administrator on Windows 11 Pro 24H2
2. Enable Hyper-V, Virtual Machine Platform, Windows Hypervisor Platform via optionalfeatures
3. Run bcdedit /set hypervisorlaunchtype auto and restart
4. Confirm all services running: CoworkVMService, vmcompute, vmms
5. Open Claude Desktop, navigate to Cowork tab
6. Observe: "Virtualization is not available" error — VM never initializes

Claude Model

Not sure / Multiple models

Is this a regression?

Yes, this worked in a previous version

Last Working Version

Yes (machine was previously Windows 11 Home, upgraded to Pro — error message changed but Cowork still fails)

Claude Code Version

Claude Desktop v1.1.9310.0

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

Is this a regression? — Yes
Last Working Version — Never worked (fresh install after OS upgrade)
Platform — claude.ai
Operating System — Windows 11 Pro 24H2 (Build 26100.4652)
Terminal/Shell — PowerShell
Machine was originally Windows 11 Home Single Language — Hyper-V was correctly shown as unavailable. After upgrading to Pro and enabling full Hyper-V, the error changed from "Hyper-V not available" to "virtualization service not responding", indicating the platform is now detected but communication with the service fails. Reinstalling as admin and manually starting all services did not help. Related: #27316, #27420, #29887, #32004, #36365